IPhone 4
The iPhone 4 is an iOS smartphone developed by Apple Inc. Following a number of notable leaks, the iPhone 4 was first unveiled on June 7, 2010 at Apple's Worldwide Developers Conference in San Francisco. and was released on June 24, 2010, in various countries. The iPhone 4 introduced a new hardware design to the iPhone line, incorporating an uninsulated stainless steel frame which doubles as an antenna, with internal components situated between chemically strengthened aluminosilicate glass. With these changes, Apple claimed that the iPhone 4 was the thinnest smartphone in the world. The iPhone 4 also introduced Apple's new Retina Display technology; while maintaining the same physical size and display resolution as its precursors, its liquid crystal display had a pixel density of 326 pixels per inch, which Apple's CEO Steve Jobs claimed was higher than what a human's retina could distinguish at an average distance. The iPhone 4 also introduced Apple's A4 system-on-chip, along with iOS 4—which notably introduced multitasking functionality and Apple's new FaceTime video chat service. The iPhone 4 was also the first iPhone to be released in a version for CDMA networks. The iPhone 4 received generally positive reception, with critics praising its revamped design and more powerful hardware in comparison to previous models; however, the launch of the iPhone 4 was plagued by highly publicized reports that abnormalities in its antenna design caused the device to lose its cellular signal if held in a certain way. The iPhone 4 spent the longest tiem as the Apple's flagship phone for 15 months and had the longest lifespan of the phone had produced, spanning close to four years and available in some developing countries until early 2015. Although the succeeding iPhone 4S was announced in October 2011, the 4 continued to be sold as a midrange model until September 2012, and thereafter as the entry-level offering in Apple's lineup until September 2013 with the announcement of iPhone 5S and iPhone 5C. The phone was later replaced by iPhone 4S (8GB). A lot of students such as Adrina Soo, Annabel Lim and Ong Lifen currently used iPhone 4 until a final changeover that had happened in August 2011 to March 2012. Customers are advised to retire their iPhone 4 before 2016. The iPhone 4 is considered obsolete from 16 July 2016. History Before the official unveiling of the iPhone 4 in June 7, 2010, two prototypes were brought to the attention of the media, breaching Apple's normally secretive development process. Many of the speculations regarding technical specifications proved accurate. Software The iPhone 4 shipped with iOS 4, which was the newest version of Apple's iOS mobile operating system at the time. iOS 4 introduced a multitasking system, allowing apps to remain "suspended" in memory, perform certain operations in the background, and allowing users to switch between apps using an on-screen menu. It also introduced FaceTime, which allows users to perform video calls between other iPhone, iPad, iPod Touch, and OS X users. The iPhone 4 supports up to iOS 7 which was released in September 2013. Due to the relatively aged hardware of the iPhone 4, certain features available on newer iPhone models are not available on the device; as of iOS 7, they include Siri, 3D maps and turn-by-turn navigation, AirDrop, AirPlay mirroring, live camera filters, panorama mode and certain visual effects introduced by iOS 7, such as the blurring of translucent interface elements, the parallax effect on the home screen, and live wallpapers. While still subject to the same limitations, iOS 7.1 did bring some slight performance improvements to the operating system on the iPhone 4. iOS 7, specifically iOS 7.1.2, is the last version of iOS to support the iPhone 4. Unlike the iPhone 4S, iPhone 4 did not receive iOS 8 due to performance issues.